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CVE-2026-105933 Apache Software Foundation CVE debrief

Apache Pulsar allows an administrator to require end-to-end message encryption for all topics in a namespace by setting the encryption_required namespace policy. When this policy is set, the broker rejects messages that are published without encryption. However, if a step of topic initialization fails, the broker logs a warning, disables the encryption requirement for that topic, and completes the topic load as if it had succeeded. This results in the topic being served with encryption_required not enforced, even though the namespace policy requires it. An authenticated client with permission to produce to the affected topic can publish messages that are not encrypted, and the broker accepts and stores them.

Vendor
Apache Software Foundation
Product
Apache Pulsar
CVSS
LOW 2.3
CISA KEV
Not listed in stored evidence
Original CVE published
2026-10-21
Original CVE updated
2026-10-23
Advisory published
2026-10-21
Advisory updated
2026-10-23

Who should care

Defenders responsible for Apache Pulsar deployments should assess their exposure and verify the encryption configuration for their namespaces and topics. This includes reviewing topic initialization logs and ensuring that encryption_required policies are enforced.

Why it matters

Defenders should prioritize verifying encryption configuration for Apache Pulsar namespaces and topics to prevent unauthorized message publication. The vulnerability allows authenticated clients to publish unencrypted messages to affected topics if encryption_required policies are not enforced due to topic initialization failures.

  • Defenders need to verify encryption configuration to prevent unauthorized message publication
  • Encryption requirement may not be enforced for topics with initialization failures
  • Authenticated clients may publish unencrypted messages to affected topics
  • Broker may accept and store unencrypted messages

Technical summary

The vulnerability occurs when a step of topic initialization fails, causing the broker to disable the encryption requirement for that topic. This allows an authenticated client with permission to produce to the affected topic to publish unencrypted messages, which are then accepted and stored by the broker. Defenders should prioritize verifying the encryption configuration for Apache Pulsar namespaces and topics, ensuring that encryption_required policies are enforced. This includes reviewing topic initialization logs for warnings and verifying that encryption is properly configured for producers. The CVE record and source item provide details on the vulnerability, including its description, CVSS score, and A

Defensive priority

Defenders should prioritize verifying the encryption configuration for Apache Pulsar namespaces and topics, ensuring that encryption_required policies are enforced. This includes reviewing topic initialization logs for warnings and verifying that encryption is properly configured for producers.

Recommended defensive actions

  • Verify encryption configuration for Apache Pulsar namespaces and topics
  • Review topic initialization logs for warnings
  • Ensure encryption_required policies are enforced
  • Update to a fixed version of Apache Pulsar if necessary
  • Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up
  • Review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance
  • Plan vendor-supported updates or mitigations through normal change control where exposure is confirmed

Evidence notes

The CVE record and source item provide details on the vulnerability, including its description, CVSS score, and affected versions. The vendor has provided references to their advisory and a mailing list discussion.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-105933 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-105933

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-105933 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-105933

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.